Contact device



April 3, 1951 v M. F. JONES ETAL 2,547,214

CONTACT DEVICE Filed April 16, 1947 Fig. 1.

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INVENTORS Maurice FJbnes and Rue! C. Jonefi.

Patented Apr. 3, 1951 .UNITED STATES PATENT OFFICE CONTACT DEVICE Maurice F. Jones and Rue! C. Jones, Pittsburgh,

Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh; Pa., a corporation of Pennsylvania Application April 16, 1947, Serial No. 741,910

' which are actuated by operatin elements travelling at extremely high speeds.

Where it is necessary to actuate electric switches by an operating member moving at a high speed, known types of switches are unreliable at least at speeds of the operating member in excess of about 140 miles per hour. Thus where contacts are to be actuated under these conditions for the purpose of measuring the speed of the operating member it is impossible to obtain an accurate record of such speed if the switch device is not reliable in operation, and this is particularly true where a number of switches are positioned along the path of travel of the operating member and each switch must be operated to close and then open its contacts before the next succeeding switch is operated.

Accordingly, one object of this invention is to provide a novel electric switch structure capable of dependable operation by a switch actuating member which travels at extremelyhigh speeds.

Another object of this invention is to provide novel electrc switching apparatus which is capabit} of first making and then breaking the circuit therethrough in a dependable manner upon actuation by an operating member travelling. at extremely high speeds.

A more specific object of this invention is to provide a novel switch device having a flexible movable contacting member adapted to be directly engaged by a high speed operating member to perform a switching operation.

. Still another object of this invention is to provide a novel switch structure having a flexible movable switch member adapted to movably engage one line terminal at least during fiexure of said member into engagement with the other line terminal, after which the member is disengaged from one terminal.

f'I'hese and other objects of this invention will become more apparent upon consideration of the following detailed description of preferred embgdiments thereof, when taken in connection with the attached drawing, in which:

Figure 1 is a circuit diagram illustrating one use of the switch comprising this invention;

Fig. 2 is a front View of a switch constructed in accordance with this invention showing the switch operating member in section;

Fig. 3 is a side view of the switch shown in Fig.2;

,4 is a partial side view of a modified switch? and 2 Fig. 5 is a section taken substantially on the line VV of Fig. 4.

While this invention is applicable to switches which are operated by actuating members trav-' elling at high speeds generally, only one such applicationin speed measuring device is disclosed herein where a plurality of switches are operated by the device whose speed is to. be measured to provide a suitable indication of the rate of movement of the device. Accordingly, while it should be distinctly understood that the switch comprising this invention is of general application, for purposes of illustration it is disclosed herein as being embodied in an arrangement for measuring the speed of devices in one particular speed measuring arrangement.

The particular speed measuring device or chronograph shown in Fig. 1 of the drawing comprises supply conductors 2 and 4 which may be energized by any suitable source of electrical energy, and across which are connected a plurality of parallel indicator circuits 6. Each indicator circuit 6 comprises a series arrangement of a resistor 8 and condenser NJ, with the primary coil of a transformer 12 connected across the condenser ID, in a circuit which is normally open at the switch I. The secondary coil of transformer i2 is connected across a small air gap l6.

In the operation of the system shown in Fig. 1, the switches M are placed at known equal distances apart along the path of travel of the device whose speed is to be measured so as to be actuated by the device in passing the location of each switch I4.

switches I4 are required to close the circuit through the primary coil of transformer [2 when the switches are actuated so as to discharge condenser IO through the primary coil, and then to open the circuit of this coil before the next switch 14 is actuated. Discharge of condenser Id order to obtain a measurement of speed, air gaps is are assembled in any suitable manner with indicating means, which may comprise a strip of paper or the like which is moved at a constant speed through the air gaps, so that when each gap arcs over a small hole is burned through the paper, and the speed can then be determined by measuring the distance between these holes. The particular means for collecting and arriving at the speed or other measurement forms no part i i this. in en on, exce to...il s e he m- It will be observed that the portance of obtaining dependable operation of switches '14, because in the particular speed measuring system shown in Fig. 1, the whole operation thereof depends upon consistent operation of switches l 4.

One embodiment of switch I4 is illustrated in Figs. 2 and 3 as comprising a supporting base I8 of insulating material, preferably a molded insulating material on which is mounted at one end a contact terminal rod 20 of some good electrical conducting material, such as copper or brass, and at a spaced point a second contact terminal rod 22 is mounted. The contact rods are mounted on supporting base l8 preferably by extending through openings in the supporting base and being secured to the base as by nuts 24 threaded on the contact rods at each side of the supporting base. Conductor clamps 26 are secured to each contact rod by one of the nuts 24 for securing a circuit conductor thereto.

A supporting rod 28 is also mounted on supporting base 18 in the same manner as contact rods 20 and 22,'an d this'supporting rod 28 may be of insulating material if desired, although this is not necessary inasmuch as it is insulated from the contact rods by supporting base [8. The movable member of switch l4 comprises a wire 3!] of any good flexible electrical conducting material, such as copper, and this is normally supported at one end on supporting rod 28 in a fixed manner, as by having a loop around supporting rod '28 with the end of wire 30 wrapped several turns on itself as at 32 to fixedly secure this end of the wire 30 to the rod 28. The wire extends directly to contact rod 22 and has one turn about this rod as at 34, which is tight enough to maintain the wire out of engagement with contact rod 20.

Supporting base I8 for the switch may be sup ported so that wire 30 is inthe path of movement of an actuating lug 40 of a device which travels at high speed in a direction from left to right as viewed-in Fig. 2, and the speed of which is to be measured. A supporting bracket 36 is illustrated the circuit will be made and broken by the high speed operating lug 48 because it carries wire 30 with it into engagement with contact rod 28 to make the circuit, and then continues to carry wire 30 with it'away from contact rod 22 and throws it to a position remote from rod 22. ,In the embodiment of the invention shown in Figs. 2 and 3, the movable contact member of switch 14 may be made up in advance for purposes of convenience of proper length with a preformed loop of a size to readily slip over the end of supporting rod 28. The other end of wire 3Q may then be wound around contact rod 22, preferably at least one fullturn and tight enough to hold the wire clear of contact rod 20, as previously explained. While the size of wire 30 is not critical, it must be large enough as not to be subject to false operation due to air pressure built up in front of the high speed actuating member. Thus for example, where annealed copper wire was used, it was found that for speeds of the operating member above miles per hour wire of .032" diameter gave satisfactory operation. On the other hand, it was found that wire only as large on the order of .01 to .02" diameter gave false indications. Generally speaking, the size of wire 30 should be be kept small in the interest of flexibility and it is merely desired to point out that it can not be too small and still give reliable operation.

Inasmuch as wires 30 may be broken or otherwise damaged on each operation, it may be desirable in some cases to have a supply of wire incorporated with the'switch so that the moveable contact member is more readily renewable. Such an arrangement is illustrated in Figs. 4 and 5 of the drawing wherein a supporting rod 42 is provided for a supply of wire 30, with the rod having an integral flange 44 held against supporting base [8 by a nut 46 threaded on the rod at the opposite side of the supporting base l8. A spool 41 of wire 36 is rotatably mounted on the outer end of rod 42, being held on the rod by a nut 48. Spool 41 has fixed thereto a ratchet wheel 50 at the end adjacent supporting base 18, for cooperation with a pawl lever 52 rotatably mounted on a pivot pin '54 secured in supporting base 18 and biased toengage the teeth of ratchet Wheel 50 by a leaf spring 56 secured to pivot pin 5:: and engaging the outer end of pawllever 52.

In the operation of the embodiment of the invention shown in Figs. 4 and 5, it will be apparent that when it is desiredto place theswitch in condition for operation, a proper length of wire 30 may be unrolled from spool 41 by manually holding pawl lever 52 disengaged from ratchet wheel 56. When the proper length of wire has been unrolled from the spool 41, the pawl lever 52 may be released and the wire pulled taut and wrapped around a contact rod 22 in the manner shown in Figs. 2 and 3. It will be apparent that following any operation of the switch, the movable contactmember comprising the proper length of wire 30 may be renewed in the same manner in a relatively quick and easy fashion. When the switch is being operated, it will be observed that pawl lever 52 by its engagement with ratchet wheel 50 holds the end of wire 35 on spool 41 at a fixed position.

In the foregoing it is pointed out wherein a switch constructed in accordance with this invention is especially adapted for dependable 'operation, particularly when actuated by an operating member moving at high speeds. Moreover, the invention provides a switch having a movable contact member of flexible material which is normally held at an open circuit position by engagement with one circuit terminal and an insulating support at a position to be engaged by an operating member, so as to be flexed into engagement with the other terminal of the circuit while remaining in frictional engagement with the first terminal to close the circuit, after Having described preferred embodiments of the invention as required by the patent statutes, it is desired that this invention be not limited to the particular structures disclosed, or ,as previously pointed out that it be not limited for use with the particular circuit illustrated, inasmuch as many changes in structure and many other uses of the structure will be apparent to persons skilled in the art. Accordingly, it is desired that this invention be interpreted as broadly as possible, and that it be limited as required by the prior art.

We claim as our invention:

1. In an electric switching device, a movable switch member at least a portion of which is flexible, a line terminal, spaced supports for said member one of which is a second line terminal spaced from the first-mentioned terminal and the other of which is insulated from both terminals, said supports normally spacing said member from said first-mentioned line terminal, and said switch member having releasable frictional engagement with one of said supports so that when said member is moved in one direction it flexes to engage said first line terminal and thereafter it is disconnected from said one support.

2. In an electric switching device, a movable switch member at least a portion of which is flexible, a line terminal, spaced supports for said member one of which is a second line terminal spaced from the first-mentioned terminal and the other of which is insulated from both terminals," said supports normally spacing said member, from said first-mentioned line terminal, and said member having frictional engagement with said line terminal support sothat when said member is moved in one direction it flexes into engagement with said first line terminal and thereafter is disconnected from said line terminal support.

3. In an electric switching device, a movable switch member at least a portion of which is flexible, a line terminal, spaced supports for said member one of which is a second line terminal spaced from the first-mentioned terminal and the other of which is insulated from both terminals, said supports normally spacing said member from said first-mentioned line terminal, and said member being movably connected with one of said supports in a manner such that it is movable azpredetermined amount relative to said one support and in response to additional movement is disengaged from said one support, so that when said member is actuated at an'intermediate point it will be moved in one direction to flex and engage said first line terminal and thereafter be disconnected from one of said line terminals.

4. In an electric switching device, a movable switch member at least a portion of which is flexible, a line terminal, spaced supports for said member one of which is a second line terminal spaced from the first-mentioned terminal and the other of which is insulated from both terminals, said supports normally spacing said member from said first-mentioned line terminal, and said-member being secured to one of said supports and being releasably frictionally mounted on the other of said supports so that when said member is actuated at an intermediate point it :i

will be flexed in a direction to engage said first line terminal and thereafter be disconnected from one of said line terminals.

5. In an electric switching device, a movable switch member the major portion of which is flexible, a line terminal, spaced supports for said member one of which is a second line terminal spaced from the first-mentioned terminal and the other of which is insulated from both terminals, said supports normally spacing said member from said first-mentioned'line terminal, and said member'being releasably frictionally engaged with one of said supports so that when said member is moved in a direction it will flex to engage said first line terminal and thereafter be disconnected from one of said line terminals.

6. In an electric switching device, spaced line terminals, an insulated support oifset laterally and longitudinally beyond said terminals, a flexible strip of conducting material secured to said support and extending directly to and being bent about the more remote of said line terminals but being otherwise unsecured thereto, so that when the strip is engaged at an intermediate point by an actuating member it will first flex to engage the other of said terminals while remaining in frictional engagement with said remote terminal so that said terminals are bridged, and thereafter it will be pulled out of engagement with at least said more remote line terminal.

7. In an electric switching device, spaced line terminals, an insulated support oifset laterally and longitudinally beyond said terminals, a roll of flexible and conducting strip material rotatably mounted on said support, manually releasable means for preventing rotation of said roll on said support so that said strip material may extend from said roll directly to the more remote of said line terminals to be bent about said terminal but being otherwise unsecured thereto, so that when the strip is engaged at an intermediate point by an actuating member it will flex to engage the other of said terminals while remaining in frictional engagement with said remote terminal so that said terminals are bridged, and thereafter it will be pulled out of engagement with at least said more remote line terminal.

8. In an electric switching device, spaced line terminals, an insulated support offset laterally and longitudinally beyond said terminals, a flexible wire of conducting material secured to said support and extending directly to and being bent about the more remote of said line terminals but being otherwise unsecured thereto, so that when the wire is engaged at an intermediate point by an actuating member it will flex to engage the other of said terminals while remaining in frictional engagement with said remote terminal so that said terminals are bridged, and thereafter it will be pulled out of engagement with at least said more remote line terminal.

9. In an electric switching device, spaced line terminals, an insulated support offset laterally and longitudinally beyond said terminals, a roll of flexible and conducting wire rotatably mounted on said support, manually releasable means for preventing rotation of said roll on said support so that said wire may extend from said roll directly to and be bent about the more remote of said line terminals but being otherwise unsecured thereto, so that when the wire is engaged at an intermediate point by an actuating member it will fiex to engage the other of said terminal while remaining in frictional engagement with said remote terminal so that said terminals are bridged, and thereafter it will be pulled out of engagement with at least said more remote line terminal.

10. In an electric switching device, a movable switch member at least a portion of which is flexible, a line terminal, spaced supports for said member one of which is a second line terminal spaced from the first-mentioned terminal and the other of which is insulated from both terminals, said supports normally spacing said member from said first-mentioned line terminal, and said membe'rbein'g temporarily secured to one of said supports-by means which is responsive to actuation 013 said member at an intermediate point result-- ing in fiexure of said member to engage said first line terminal, to thereafter disengage said mem- 5 her from said one support;

MAUBICE'F. JONES"; RLUEE CI- JONES.

REFERENCES CITED The following references are of record in the.

file of this patent:

UNITED STATES PATENTS Number Name Date 1,740,107 Lewis Dec; 17', 1929 2,282,132 I Haltom et-ajL- May5, 1942 21323158 9 Mos V Apr; 10, 1945 

